The present invention relates generally to multi-board input and display systems.
Pen-based electronic systems, especially suited for classroom or learning environments, have been in use for several years. These pen-based electronic systems utilize a large touch-sensitive electronic whiteboard or similarly functioning board that is usually located at a strategic vantage point for viewing by the entire audience (e.g. at the front of the room). A user such as a moderator writes on the board and this board may thus be considered a moderator workstation. The pen-based electronic system may additionally include a pen-based video tablet or similar device for each board. A video tablet is an input and display device that does not communicate directly with a board. The board and video tablet are both connected to a single computer. The computer mirrors its output so that the output of the computer is displayed on both the video tablet and the board.
Other users of the system also have workstations augmented with video tablets. These users can use their electronic pens to make private annotations on the copy of the board material that is presented on a workspace on their pen-based video tablet. Users can also submit portions of their workspace, for example containing a solution to a problem that was worked out during instruction, to a teacher who can display this material on the board for the entire class to view and discuss. Such hardware as discussed above for the implementation of the described features is driven by what is known as groupware. Groupware is software that supports cooperative work by providing a shared work surface for two or more users. Such a system is described in U.S. patent application Ser. No. 10/689,804 by David Berque and Daniel P. Sanders entitled System For Knowledge Transfer In A Group Setting, filed Oct. 20, 2003 and its parent application, U.S. Patent Application Publication 2002/0100445 A1 (Ser. No. 09/899,431), both of which applications are specifically incorporated herein by reference.
The pen-based electronic system described above provides a shared drawing surface paradigm that differs in an important manner from a typical “WYSIWIS” (What You See Is What I See) paradigm common to typical groupware. With the above-cited pen-based system, drawing actions made by a moderator on a moderator workstation (the whiteboard) are immediately transmitted to all of the participants' workstations via a session server while the drawing actions of the participants on their workstation are not transferred to the moderator's workstation. This is because the participants' drawing actions are considered to be private. In view of this, the moderator generally has no awareness of participant drawing actions unless the moderator chooses to display a particular participant's work.
The lack of moderator awareness of participant drawing actions would appear to be a benign event. However, the lack of moderator awareness of participant drawing actions can lead to a problem that may be referred to as a collision problem. The collision problem results when the moderator adds public material to the shared drawing surface in such a manner that this material collides with private annotations that have been previously written by one or more participants. In practice, this problem is exacerbated by the fact that participants are allowed to make private annotations to the moderator's dynamically changing public material. Allowing private annotations, however, is considered an important feature, as evidenced from actual classroom experience with such systems. Particularly, allowing this type of annotation is an important feature because moderators typically draw a sketch, discuss it, enhance the sketch, and then discuss it some more. Because of this alternating pattern, it is not desirable to force the participants to annotate only frozen snapshots of the moderator's material. Rather, it is important for the participants to be able to interactively annotate the moderator's notes as they evolve.
There has been considerable prior work on supporting the private annotation of static documents such as web pages. However, this work is not directly applicable to the problem at hand due to the dynamic nature of the public content that students need to annotate. In view of this, there has been some prior work in the area of coping with collision type problems for dynamic displays in the context of so called “single display groupware systems.” This paradigm is characterized by two or more co-located users, each with his/her own input device, interacting using a single shared display. When interacting using a single display, it is possible for the actions of one user (for example, raising a menu) to interfere with the actions of another user. The use of translucent interface components has been explored as a solution to the collision problem. Another approach is the use of shutter glasses to allow a pair of users to make private annotations to public content in the context of single display groupware. This work, however, is limited to supporting a pair of users and is most applicable in the context of single display groupware.
Collision strategies for coping with the collision problem can be divided into two broad categories: collision correction and collision avoidance. The collision correction approach assumes collisions will occur and provides mechanisms for correcting the collisions after the fact. For example, the system might allow each participant to toggle between three separate view modes: one in which only the moderator's material is displayed, one in which only that participant's material is displayed, and one in which both sets of material are displayed. The latter view might display a collision, but by toggling between the other views the student can determine the true contents of the shared work surface. Alternatively, similar to the ideas explored for collision correction solutions, the system might display annotations using translucent ink. These approaches have the disadvantages, however, of not being applicable to a printed version of the electronic notebook. A more elaborate collision resolution strategy provides the students with the ability to select and relocate some or all of the private annotations that are colliding with material drawn by the teacher. However, this technique fails in many contexts because changing the location of a private annotation may destroy its meaning.
An alternative to the collision correction strategies are collision avoidance strategies. These strategies require the provision of facilities in the system that help users avoid collisions in the first place. A simple, and perhaps the simplest, collision avoidance strategy is to provide each participant with a private margin or window separate from the shared work surface, and to require that all private annotations take place in this private area. There are several limitations associated with restricting student annotations to a private area in the WYSIWIS paradigm. First, forcing the participants to write in a separate margin or window restricts their ability to associate their annotations with the relevant public material. This can be mitigated to some extent by allowing the participants to place hyperlinks between their marginal notes and the relevant public material. Experience shows, however, that participants hardly use this feature, preferring instead to take notes directly on the moderator's public material even with the risk of collision.
With the current pen-based electronic systems, a single whiteboard of limited size (e.g. 5′W×4′H) is somewhat constraining for the typical instructor who is used to having twenty (20) feet or more of board space in a typical classroom. This typically does not allow for more than one student's work (from his or her workstation) to be displayed at one time on the single whiteboard. Additionally, the current pen-based electronic systems do not allow for instructor mobility. The instructor is limited in mobility because he/she must stay at the single whiteboard for providing written input into the system and for control of the system. If the instructor sees an interesting student solution while walking the classroom, the instructor must return to the whiteboard in order to display the student's work. This is a time-consuming procedure that leads to frustration on the part of the instructor.
What is therefore needed is a multi-board input and display system that alleviates the shortcomings of the prior art.
What is therefore further needed is a multi-board input and display system that provides mobility to a moderator of the system while allowing input, display and control of the system.